[CSS] Use strongly-typed IsImportant instead of bool

https://bugs.webkit.org/show_bug.cgi?id=276974
rdar://132359273

Reviewed by Tim Nguyen.

* Source/WebCore/animation/KeyframeEffect.cpp:
(WebCore::processIterableKeyframes):
(WebCore::processPropertyIndexedKeyframes):
* Source/WebCore/animation/WebAnimation.cpp:
(WebCore::WebAnimation::commitStyles):
* Source/WebCore/css/CSSComputedStyleDeclaration.cpp:
(WebCore::CSSComputedStyleDeclaration::setPropertyInternal):
* Source/WebCore/css/CSSComputedStyleDeclaration.h:
* Source/WebCore/css/CSSProperty.h:
(WebCore::StylePropertyMetadata::StylePropertyMetadata):
(WebCore::CSSProperty::CSSProperty):
* Source/WebCore/css/CSSStyleDeclaration.cpp:
(WebCore::CSSStyleDeclaration::setPropertyValueForCamelCasedIDLAttribute):
(WebCore::CSSStyleDeclaration::setPropertyValueForWebKitCasedIDLAttribute):
(WebCore::CSSStyleDeclaration::setPropertyValueForDashedIDLAttribute):
(WebCore::CSSStyleDeclaration::setPropertyValueForEpubCasedIDLAttribute):
(WebCore::CSSStyleDeclaration::setCssFloat):
* Source/WebCore/css/CSSStyleDeclaration.h:
* Source/WebCore/css/ComputedStyleExtractor.cpp:
(WebCore::ComputedStyleExtractor::copyProperties const):
* Source/WebCore/css/DOMCSSNamespace.cpp:
(WebCore::DOMCSSNamespace::supports):
* Source/WebCore/css/DOMMatrixReadOnly.cpp:
(WebCore::DOMMatrixReadOnly::parseStringIntoAbstractMatrix):
* Source/WebCore/css/MutableStyleProperties.cpp:
(WebCore::MutableStyleProperties::setProperty):
(WebCore::MutableStyleProperties::setCustomProperty):
* Source/WebCore/css/MutableStyleProperties.h:
* Source/WebCore/css/PropertySetCSSStyleDeclaration.cpp:
(WebCore::PropertySetCSSStyleDeclaration::setProperty):
(WebCore::PropertySetCSSStyleDeclaration::setPropertyInternal):
* Source/WebCore/css/PropertySetCSSStyleDeclaration.h:
* Source/WebCore/css/StyleProperties.cpp:
(WebCore::StyleProperties::propertyIsImportant const):
(WebCore::StyleProperties::copyProperties const):
* Source/WebCore/css/StyleProperties.h:
(WebCore::StyleProperties::PropertyReference::toCSSProperty const):
* Source/WebCore/css/parser/CSSParser.cpp:
(WebCore::CSSParser::parseValue):
(WebCore::CSSParser::parseCustomPropertyValue):
* Source/WebCore/css/parser/CSSParser.h:
* Source/WebCore/css/parser/CSSParserImpl.cpp:
(WebCore::CSSParserImpl::parseValue):
(WebCore::CSSParserImpl::parseCustomPropertyValue):
(WebCore::filterProperties):
(WebCore::createStyleProperties):
(WebCore::CSSParserImpl::parseDeclarationList):
(WebCore::CSSParserImpl::consumeTrailingImportantAndWhitespace):
(WebCore::CSSParserImpl::consumeDeclaration):
(WebCore::CSSParserImpl::consumeCustomPropertyValue):
(WebCore::CSSParserImpl::consumeDeclarationValue):
* Source/WebCore/css/parser/CSSParserImpl.h:
* Source/WebCore/css/parser/CSSPropertyParser.cpp:
(WebCore::CSSPropertyParser::addProperty):
* Source/WebCore/css/typedom/CSSStyleValueFactory.cpp:
(WebCore::CSSStyleValueFactory::extractCSSValue):
(WebCore::CSSStyleValueFactory::extractShorthandCSSValues):
* Source/WebCore/css/typedom/DeclaredStylePropertyMap.cpp:
(WebCore::DeclaredStylePropertyMap::setShorthandProperty):
(WebCore::DeclaredStylePropertyMap::setProperty):
(WebCore::DeclaredStylePropertyMap::setCustomProperty):
* Source/WebCore/css/typedom/InlineStylePropertyMap.cpp:
(WebCore::InlineStylePropertyMap::setShorthandProperty):
(WebCore::InlineStylePropertyMap::setProperty):
* Source/WebCore/dom/StyledElement.cpp:
(WebCore::StyledElement::setInlineStyleProperty):
(WebCore::StyledElement::setInlineStyleCustomProperty):
(WebCore::StyledElement::addPropertyToPresentationalHintStyle):
* Source/WebCore/dom/StyledElement.h:
* Source/WebCore/editing/ApplyStyleCommand.cpp:
(WebCore::ApplyStyleCommand::applyRelativeFontStyleChange):
* Source/WebCore/editing/EditingStyle.cpp:
(WebCore::EditingStyle::setProperty):
(WebCore::EditingStyle::extractAndRemoveTextDirection):
(WebCore::EditingStyle::collapseTextDecorationProperties):
(WebCore::EditingStyle::conflictsWithInlineStyleOfElement const):
(WebCore::EditingStyle::mergeStyle):
(WebCore::EditingStyle::forceInline):
(WebCore::EditingStyle::convertPositionStyle):
(WebCore::setTextDecorationProperty):
* Source/WebCore/editing/EditingStyle.h:
* Source/WebCore/editing/Editor.cpp:
(WebCore::Editor::setBaseWritingDirection):
* Source/WebCore/editing/ReplaceSelectionCommand.cpp:
(WebCore::ReplaceSelectionCommand::removeRedundantStylesAndKeepStyleSpanInline):
* Source/WebCore/html/AttachmentAssociatedElement.cpp:
(WebCore::AttachmentAssociatedElement::setAttachmentElement):
* Source/WebCore/html/ColorInputType.cpp:
(WebCore::ColorInputType::updateColorSwatch):
* Source/WebCore/html/TextFieldInputType.cpp:
(WebCore::TextFieldInputType::createShadowSubtree):
(WebCore::TextFieldInputType::createDataListDropdownIndicator):
(WebCore::TextFieldInputType::capsLockStateMayHaveChanged):
(WebCore::TextFieldInputType::updateAutoFillButton):
(WebCore::TextFieldInputType::dataListMayHaveChanged):
* Source/WebCore/html/shadow/MediaControlTextTrackContainerElement.cpp:
(WebCore::MediaControlTextTrackContainerElement::updateTextStrokeStyle):
* Source/WebCore/html/shadow/TextPlaceholderElement.cpp:
* Source/WebCore/html/track/VTTCue.cpp:
(WebCore::VTTCueBox::applyCSSProperties):
* Source/WebCore/page/DragController.cpp:
(WebCore::DragController::concludeEditDrag):
* Source/WebCore/style/PropertyCascade.cpp:
(WebCore::Style::PropertyCascade::addMatch):
(WebCore::Style::PropertyCascade::addNormalMatches):
(WebCore::Style::PropertyCascade::addImportantMatches):
* Source/WebCore/style/PropertyCascade.h:
* Source/WebCore/svg/properties/SVGAttributeAnimator.cpp:
(WebCore::SVGAttributeAnimator::applyAnimatedStylePropertyChange):

Canonical link: https://commits.webkit.org/281329@main

Source/WebCore/animation/KeyframeEffect.cpp

@@ -380,9 +380,9 @@ static inline ExceptionOr<void> processIterableKeyframes(JSGlobalObject& lexical
             auto stringValue = propertyAndValue.values[0];
             if (cssPropertyId == CSSPropertyCustom) {
                 auto customProperty = propertyAndValue.customProperty;
-                if (keyframeOutput.style->setCustomProperty(customProperty, stringValue, false, parserContext))
+                if (keyframeOutput.style->setCustomProperty(customProperty, stringValue, parserContext))
                     keyframeOutput.customStyleStrings.set(customProperty, stringValue);
-            } else if (keyframeOutput.style->setProperty(cssPropertyId, stringValue, false, parserContext))
+            } else if (keyframeOutput.style->setProperty(cssPropertyId, stringValue, parserContext))
                 keyframeOutput.styleStrings.set(cssPropertyId, stringValue);
         }
 
@@ -422,9 +422,9 @@ static inline ExceptionOr<void> processPropertyIndexedKeyframes(JSGlobalObject&
             // 2. Add the property-value pair, property name → v, to k.
             if (propertyName == CSSPropertyCustom) {
                 auto customProperty = m.customProperty;
-                if (k.style->setCustomProperty(customProperty, v, false, parserContext))
+                if (k.style->setCustomProperty(customProperty, v, parserContext))
                     k.customStyleStrings.set(customProperty, v);
-            } else if (k.style->setProperty(propertyName, v, false, parserContext))
+            } else if (k.style->setProperty(propertyName, v, parserContext))
                 k.styleStrings.set(propertyName, v);
             // 3. Append k to property keyframes.
             propertyKeyframes.append(WTFMove(k));

Source/WebCore/animation/WebAnimation.cpp

@@ -1609,12 +1609,12 @@ ExceptionOr<void> WebAnimation::commitStyles()
         return WTF::switchOn(property,
             [&] (CSSPropertyID propertyId) {
                 if (auto cssValue = computedStyleExtractor.valueForPropertyInStyle(*animatedStyle, propertyId, nullptr, ComputedStyleExtractor::PropertyValueType::Computed))
-                    return inlineStyle->setProperty(propertyId, cssValue->cssText(), false, { styledElement->document() });
+                    return inlineStyle->setProperty(propertyId, cssValue->cssText(), { styledElement->document() });
                 return false;
             },
             [&] (const AtomString& customProperty) {
                 if (auto cssValue = computedStyleExtractor.customPropertyValue(customProperty))
-                    return inlineStyle->setCustomProperty(customProperty, cssValue->cssText(), false, { styledElement->document() });
+                    return inlineStyle->setCustomProperty(customProperty, cssValue->cssText(), { styledElement->document() });
                 return false;
             }
         );

Source/WebCore/css/CSSComputedStyleDeclaration.cpp

@@ -267,7 +267,7 @@ String CSSComputedStyleDeclaration::getPropertyValueInternal(CSSPropertyID prope
     return getPropertyValue(propertyID);
 }
 
-ExceptionOr<void> CSSComputedStyleDeclaration::setPropertyInternal(CSSPropertyID, const String&, bool)
+ExceptionOr<void> CSSComputedStyleDeclaration::setPropertyInternal(CSSPropertyID, const String&, IsImportant)
 {
     return Exception { ExceptionCode::NoModificationAllowedError };
 }

Source/WebCore/css/CSSComputedStyleDeclaration.h

@@ -70,7 +70,7 @@ class CSSComputedStyleDeclaration final : public CSSStyleDeclaration, public Ref
     String cssText() const final;
     ExceptionOr<void> setCssText(const String&) final;
     String getPropertyValueInternal(CSSPropertyID) final;
-    ExceptionOr<void> setPropertyInternal(CSSPropertyID, const String& value, bool important) final;
+    ExceptionOr<void> setPropertyInternal(CSSPropertyID, const String& value, IsImportant) final;
     Ref<MutableStyleProperties> copyProperties() const final;
 
     RefPtr<CSSValue> getPropertyCSSValue(CSSPropertyID, ComputedStyleExtractor::UpdateLayout = ComputedStyleExtractor::UpdateLayout::Yes) const;

Source/WebCore/css/CSSProperty.h

@@ -31,12 +31,14 @@ namespace WebCore {
 
 class CSSValueList;
 
+enum class IsImportant : bool { No, Yes };
+
 struct StylePropertyMetadata {
-    StylePropertyMetadata(CSSPropertyID propertyID, bool isSetFromShorthand, int indexInShorthandsVector, bool important, bool implicit, bool inherited)
+    StylePropertyMetadata(CSSPropertyID propertyID, bool isSetFromShorthand, int indexInShorthandsVector, IsImportant important, bool implicit, bool inherited)
         : m_propertyID(propertyID)
         , m_isSetFromShorthand(isSetFromShorthand)
         , m_indexInShorthandsVector(indexInShorthandsVector)
-        , m_important(important)
+        , m_important(important == IsImportant::Yes)
         , m_implicit(implicit)
         , m_inherited(inherited)
     {
@@ -48,17 +50,17 @@ struct StylePropertyMetadata {
 
     friend bool operator==(const StylePropertyMetadata&, const StylePropertyMetadata&) = default;
 
-    uint16_t m_propertyID : 10;
-    uint16_t m_isSetFromShorthand : 1;
-    uint16_t m_indexInShorthandsVector : 2; // If this property was set as part of an ambiguous shorthand, gives the index in the shorthands vector.
-    uint16_t m_important : 1;
-    uint16_t m_implicit : 1; // Whether or not the property was set implicitly as the result of a shorthand.
-    uint16_t m_inherited : 1;
+    unsigned m_propertyID : 10;
+    unsigned m_isSetFromShorthand : 1;
+    unsigned m_indexInShorthandsVector : 2; // If this property was set as part of an ambiguous shorthand, gives the index in the shorthands vector.
+    unsigned m_important : 1;
+    unsigned m_implicit : 1; // Whether or not the property was set implicitly as the result of a shorthand.
+    unsigned m_inherited : 1;
 };
 
 class CSSProperty {
 public:
-    CSSProperty(CSSPropertyID propertyID, RefPtr<CSSValue>&& value, bool important = false, bool isSetFromShorthand = false, int indexInShorthandsVector = 0, bool implicit = false)
+    CSSProperty(CSSPropertyID propertyID, RefPtr<CSSValue>&& value, IsImportant important = IsImportant::No, bool isSetFromShorthand = false, int indexInShorthandsVector = 0, bool implicit = false)
         : m_metadata(propertyID, isSetFromShorthand, indexInShorthandsVector, important, implicit, isInheritedProperty(propertyID))
         , m_value(WTFMove(value))
     {

Source/WebCore/css/CSSStyleDeclaration.cpp

@@ -261,7 +261,7 @@ ExceptionOr<void> CSSStyleDeclaration::setPropertyValueForCamelCasedIDLAttribute
 {
     auto propertyID = lookupCSSPropertyFromIDLAttribute<CSSPropertyLookupMode::ConvertUsingNoDashPrefix>(attribute);
     ASSERT_WITH_MESSAGE(propertyID != CSSPropertyInvalid, "Invalid attribute: %s", attribute.string().utf8().data());
-    return setPropertyInternal(propertyID, value, false);
+    return setPropertyInternal(propertyID, value, IsImportant::No);
 }
 
 String CSSStyleDeclaration::propertyValueForWebKitCasedIDLAttribute(const AtomString& attribute)
@@ -275,7 +275,7 @@ ExceptionOr<void> CSSStyleDeclaration::setPropertyValueForWebKitCasedIDLAttribut
 {
     auto propertyID = lookupCSSPropertyFromIDLAttribute<CSSPropertyLookupMode::ConvertUsingDashPrefix>(attribute);
     ASSERT_WITH_MESSAGE(propertyID != CSSPropertyInvalid, "Invalid attribute: %s", attribute.string().utf8().data());
-    return setPropertyInternal(propertyID, value, false);
+    return setPropertyInternal(propertyID, value, IsImportant::No);
 }
 
 String CSSStyleDeclaration::propertyValueForDashedIDLAttribute(const AtomString& attribute)
@@ -289,7 +289,7 @@ ExceptionOr<void> CSSStyleDeclaration::setPropertyValueForDashedIDLAttribute(con
 {
     auto propertyID = lookupCSSPropertyFromIDLAttribute<CSSPropertyLookupMode::NoConversion>(attribute);
     ASSERT_WITH_MESSAGE(propertyID != CSSPropertyInvalid, "Invalid attribute: %s", attribute.string().utf8().data());
-    return setPropertyInternal(propertyID, value, false);
+    return setPropertyInternal(propertyID, value, IsImportant::No);
 }
 
 String CSSStyleDeclaration::propertyValueForEpubCasedIDLAttribute(const AtomString& attribute)
@@ -303,7 +303,7 @@ ExceptionOr<void> CSSStyleDeclaration::setPropertyValueForEpubCasedIDLAttribute(
 {
     auto propertyID = lookupCSSPropertyFromIDLAttribute<CSSPropertyLookupMode::ConvertUsingDashPrefix>(attribute);
     ASSERT_WITH_MESSAGE(propertyID != CSSPropertyInvalid, "Invalid attribute: %s", attribute.string().utf8().data());
-    return setPropertyInternal(propertyID, value, false);
+    return setPropertyInternal(propertyID, value, IsImportant::No);
 }
 
 String CSSStyleDeclaration::cssFloat()
@@ -313,7 +313,7 @@ String CSSStyleDeclaration::cssFloat()
 
 ExceptionOr<void> CSSStyleDeclaration::setCssFloat(const String& value)
 {
-    return setPropertyInternal(CSSPropertyFloat, value, false /* important */);
+    return setPropertyInternal(CSSPropertyFloat, value, IsImportant::No);
 }
 
 }

Source/WebCore/css/CSSStyleDeclaration.h

@@ -20,14 +20,14 @@
 
 #pragma once
 
+#include "CSSProperty.h"
 #include "CSSPropertyNames.h"
 #include "ExceptionOr.h"
 #include "ScriptWrappable.h"
 #include <wtf/CheckedRef.h>
 
 namespace WebCore {
 
-class CSSProperty;
 class CSSRule;
 class CSSStyleSheet;
 class CSSValue;
@@ -67,7 +67,7 @@ class CSSStyleDeclaration : public ScriptWrappable, public CanMakeSingleThreadWe
     // CSSPropertyID versions of the CSSOM functions to support bindings and editing.
     // Use the non-virtual methods in the concrete subclasses when possible.
     virtual String getPropertyValueInternal(CSSPropertyID) = 0;
-    virtual ExceptionOr<void> setPropertyInternal(CSSPropertyID, const String& value, bool important) = 0;
+    virtual ExceptionOr<void> setPropertyInternal(CSSPropertyID, const String& value, IsImportant) = 0;
 
     virtual Ref<MutableStyleProperties> copyProperties() const = 0;
 

Source/WebCore/css/ComputedStyleExtractor.cpp

@@ -4893,7 +4893,7 @@ Ref<MutableStyleProperties> ComputedStyleExtractor::copyProperties(std::span<con
 {
     auto vector = WTF::compactMap(properties, [&](auto& property) -> std::optional<CSSProperty> {
         if (auto value = propertyValue(property))
-            return CSSProperty(property, WTFMove(value), false);
+            return CSSProperty(property, WTFMove(value));
         return std::nullopt;
     });
     return MutableStyleProperties::create(WTFMove(vector));

Source/WebCore/css/DOMCSSNamespace.cpp

@@ -53,8 +53,7 @@ bool DOMCSSNamespace::supports(Document& document, const String& property, const
     CSSPropertyID propertyID = cssPropertyID(propertyNameWithoutWhitespace);
     if (propertyID == CSSPropertyInvalid && isCustomPropertyName(propertyNameWithoutWhitespace)) {
         auto dummyStyle = MutableStyleProperties::create();
-        constexpr bool importance = false;
-        return CSSParser::parseCustomPropertyValue(dummyStyle, AtomString { propertyNameWithoutWhitespace }, value, importance, parserContext) != CSSParser::ParseResult::Error;
+        return CSSParser::parseCustomPropertyValue(dummyStyle, AtomString { propertyNameWithoutWhitespace }, value, IsImportant::No, parserContext) != CSSParser::ParseResult::Error;
     }
 
     if (!isExposed(propertyID, &document.settings()))
@@ -70,7 +69,7 @@ bool DOMCSSNamespace::supports(Document& document, const String& property, const
         return false;
 
     auto dummyStyle = MutableStyleProperties::create();
-    return CSSParser::parseValue(dummyStyle, propertyID, value, false, parserContext) != CSSParser::ParseResult::Error;
+    return CSSParser::parseValue(dummyStyle, propertyID, value, IsImportant::No, parserContext) != CSSParser::ParseResult::Error;
 }
 
 bool DOMCSSNamespace::supports(Document& document, const String& conditionText)

Source/WebCore/css/DOMMatrixReadOnly.cpp

@@ -228,7 +228,7 @@ ExceptionOr<DOMMatrixReadOnly::AbstractMatrix> DOMMatrixReadOnly::parseStringInt
         return AbstractMatrix { };
 
     auto styleDeclaration = MutableStyleProperties::create();
-    if (CSSParser::parseValue(styleDeclaration, CSSPropertyTransform, string, true, HTMLStandardMode) == CSSParser::ParseResult::Error)
+    if (CSSParser::parseValue(styleDeclaration, CSSPropertyTransform, string, IsImportant::Yes, HTMLStandardMode) == CSSParser::ParseResult::Error)
         return Exception { ExceptionCode::SyntaxError };
 
     // Convert to TransformOperations. This can fail if a property requires style (i.e., param uses 'ems' or 'exs')

Source/WebCore/css/MutableStyleProperties.cpp

@@ -141,7 +141,7 @@ bool MutableStyleProperties::removeCustomProperty(const String& propertyName, St
     return removePropertyAtIndex(findCustomPropertyIndex(propertyName), returnText);
 }
 
-bool MutableStyleProperties::setProperty(CSSPropertyID propertyID, const String& value, bool important, CSSParserContext parserContext, bool* didFailParsing)
+bool MutableStyleProperties::setProperty(CSSPropertyID propertyID, const String& value, CSSParserContext parserContext, IsImportant important, bool* didFailParsing)
 {
     if (!isExposed(propertyID, &parserContext.propertySettings) && !isInternal(propertyID)) {
         // Allow internal properties as we use them to handle certain DOM-exposed values
@@ -163,13 +163,13 @@ bool MutableStyleProperties::setProperty(CSSPropertyID propertyID, const String&
     return parseResult == CSSParser::ParseResult::Changed;
 }
 
-bool MutableStyleProperties::setProperty(CSSPropertyID propertyID, const String& value, bool important, bool* didFailParsing)
+bool MutableStyleProperties::setProperty(CSSPropertyID propertyID, const String& value, IsImportant important, bool* didFailParsing)
 {
     CSSParserContext parserContext(cssParserMode());
-    return setProperty(propertyID, value, important, parserContext, didFailParsing);
+    return setProperty(propertyID, value, parserContext, important, didFailParsing);
 }
 
-bool MutableStyleProperties::setCustomProperty(const String& propertyName, const String& value, bool important, CSSParserContext parserContext)
+bool MutableStyleProperties::setCustomProperty(const String& propertyName, const String& value, CSSParserContext parserContext, IsImportant important)
 {
     // Setting the value to an empty string just removes the property in both IE and Gecko.
     // Setting it to null seems to produce less consistent results, but we treat it just the same.
@@ -182,7 +182,7 @@ bool MutableStyleProperties::setCustomProperty(const String& propertyName, const
     return CSSParser::parseCustomPropertyValue(*this, AtomString { propertyName }, value, important, parserContext) == CSSParser::ParseResult::Changed;
 }
 
-void MutableStyleProperties::setProperty(CSSPropertyID propertyID, RefPtr<CSSValue>&& value, bool important)
+void MutableStyleProperties::setProperty(CSSPropertyID propertyID, RefPtr<CSSValue>&& value, IsImportant important)
 {
     if (isLonghand(propertyID)) {
         setProperty(CSSProperty(propertyID, WTFMove(value), important));
@@ -235,7 +235,7 @@ bool MutableStyleProperties::setProperty(const CSSProperty& property, CSSPropert
     return true;
 }
 
-bool MutableStyleProperties::setProperty(CSSPropertyID propertyID, CSSValueID identifier, bool important)
+bool MutableStyleProperties::setProperty(CSSPropertyID propertyID, CSSValueID identifier, IsImportant important)
 {
     ASSERT(isLonghand(propertyID));
     return setProperty(CSSProperty(propertyID, CSSPrimitiveValue::create(identifier), important));

Source/WebCore/css/MutableStyleProperties.h

@@ -63,12 +63,12 @@ class MutableStyleProperties final : public StyleProperties {
     bool addParsedProperty(const CSSProperty&);
 
     // These expand shorthand properties into multiple properties.
-    bool setProperty(CSSPropertyID, const String& value, bool important, CSSParserContext, bool* didFailParsing = nullptr);
-    bool setProperty(CSSPropertyID, const String& value, bool important = false, bool* didFailParsing = nullptr);
-    void setProperty(CSSPropertyID, RefPtr<CSSValue>&&, bool important = false);
+    bool setProperty(CSSPropertyID, const String& value, CSSParserContext, IsImportant = IsImportant::No, bool* didFailParsing = nullptr);
+    bool setProperty(CSSPropertyID, const String& value, IsImportant = IsImportant::No, bool* didFailParsing = nullptr);
+    void setProperty(CSSPropertyID, RefPtr<CSSValue>&&, IsImportant = IsImportant::No);
 
     // These do not. FIXME: This is too messy, we can do better.
-    bool setProperty(CSSPropertyID, CSSValueID identifier, bool important = false);
+    bool setProperty(CSSPropertyID, CSSValueID identifier, IsImportant = IsImportant::No);
     bool setProperty(const CSSProperty&, CSSProperty* slot = nullptr);
 
     bool removeProperty(CSSPropertyID, String* returnText = nullptr);
@@ -86,7 +86,7 @@ class MutableStyleProperties final : public StyleProperties {
     int findCustomPropertyIndex(StringView propertyName) const;
 
     // Methods for querying and altering CSS custom properties.
-    bool setCustomProperty(const String& propertyName, const String& value, bool important, CSSParserContext);
+    bool setCustomProperty(const String& propertyName, const String& value, CSSParserContext, IsImportant = IsImportant::No);
     bool removeCustomProperty(const String& propertyName, String* returnText = nullptr);
 
 private:

Source/WebCore/css/PropertySetCSSStyleDeclaration.cpp

@@ -167,9 +167,9 @@ ExceptionOr<void> PropertySetCSSStyleDeclaration::setProperty(const String& prop
 
     bool changed;
     if (UNLIKELY(propertyID == CSSPropertyCustom))
-        changed = m_propertySet->setCustomProperty(propertyName, value, important, cssParserContext());
+        changed = m_propertySet->setCustomProperty(propertyName, value, cssParserContext(), important ? IsImportant::Yes : IsImportant::No);
     else
-        changed = m_propertySet->setProperty(propertyID, value, important, cssParserContext());
+        changed = m_propertySet->setProperty(propertyID, value, cssParserContext(), important ? IsImportant::Yes : IsImportant::No);
 
     didMutate(changed ? MutationType::PropertyChanged : MutationType::NoChanges);
 
@@ -217,7 +217,7 @@ String PropertySetCSSStyleDeclaration::getPropertyValueInternal(CSSPropertyID pr
     return { };
 }
 
-ExceptionOr<void> PropertySetCSSStyleDeclaration::setPropertyInternal(CSSPropertyID propertyID, const String& value, bool important)
+ExceptionOr<void> PropertySetCSSStyleDeclaration::setPropertyInternal(CSSPropertyID propertyID, const String& value, IsImportant important)
 {
     StyleAttributeMutationScope mutationScope { parentElement() };
     if (!willMutate())
@@ -226,7 +226,7 @@ ExceptionOr<void> PropertySetCSSStyleDeclaration::setPropertyInternal(CSSPropert
     if (!isExposed(propertyID))
         return { };
 
-    if (m_propertySet->setProperty(propertyID, value, important, cssParserContext())) {
+    if (m_propertySet->setProperty(propertyID, value, cssParserContext(), important)) {
         didMutate(MutationType::PropertyChanged);
         mutationScope.enqueueMutationRecord();
     } else

Source/WebCore/css/PropertySetCSSStyleDeclaration.h

@@ -79,7 +79,7 @@ class PropertySetCSSStyleDeclaration : public CSSStyleDeclaration {
     String cssText() const final;
     ExceptionOr<void> setCssText(const String&) final;
     String getPropertyValueInternal(CSSPropertyID) final;
-    ExceptionOr<void> setPropertyInternal(CSSPropertyID, const String& value, bool important) final;
+    ExceptionOr<void> setPropertyInternal(CSSPropertyID, const String& value, IsImportant) final;
 
     Ref<MutableStyleProperties> copyProperties() const final;
     bool isExposed(CSSPropertyID) const;

Source/WebCore/css/StyleProperties.cpp

@@ -396,7 +396,7 @@ Ref<MutableStyleProperties> StyleProperties::copyProperties(std::span<const CSSP
 {
     auto vector = WTF::compactMap(properties, [&](auto& property) -> std::optional<CSSProperty> {
         if (auto value = getPropertyCSSValue(property))
-            return CSSProperty(property, WTFMove(value), false);
+            return CSSProperty(property, WTFMove(value));
         return std::nullopt;
     });
     return MutableStyleProperties::create(WTFMove(vector));

Source/WebCore/css/StyleProperties.h

@@ -63,7 +63,7 @@ class StyleProperties : public RefCounted<StyleProperties> {
         CSSValue* value() { return const_cast<CSSValue*>(m_value); }
 
         // FIXME: Remove this.
-        CSSProperty toCSSProperty() const { return CSSProperty(id(), const_cast<CSSValue*>(m_value), isImportant(), m_metadata.m_isSetFromShorthand, m_metadata.m_indexInShorthandsVector, isImplicit()); }
+        CSSProperty toCSSProperty() const { return CSSProperty(id(), const_cast<CSSValue*>(m_value), isImportant() ? IsImportant::Yes : IsImportant::No, m_metadata.m_isSetFromShorthand, m_metadata.m_indexInShorthandsVector, isImplicit()); }
 
     private:
         const StylePropertyMetadata& m_metadata;